Albert Mathieu presented Napoleon with a scheme for a tunnel
during the brief Peace of Amiens in 1802Fanciful scheme for a French invasion
of England during the Napoleonic Wars (cartoon drawn
c.1804.

Why wasn't it built before?It was technically possible to build
a Channel Tunnel for well over a century before it was
finally built. Why the delay?

First impractical suggestions in
the Napoleonic Wars
Two centuries ago, the idea of a road tunnel was suggested
to Napoleon during a brief peace
between France and England in 1802. But war soon broke out
again: the cartoon left is a joke, showing invading French
troops walking under the sea in a road tunnel and flying
over in balloons (the channel was first crossed by hot-air
balloon in 1785).

Both schemes existed only on paper. They lacked the
technology to overcome the problems, and did not have the
necessary geological knowledge. They guessed that the chalk
of Cap Blanc Nez ran under the sea all the way to the white
cliffs of Dover - no-one really knew. They imagined
horse-drawn carriages driving down a wood-propped tunnel
like mines of the day, lit by candles.

A railway tunnel -
a cure for seasickness!
The first steam locomotives hauled passenger trains in the
1820's. By 1850 , steam railways
were running most of the way from Paris to Calais, and from
London to Dover. Crossing the stormy channel in the small
ferries of the day was the part of
the journey that most travellers dreaded.

Victorian engineers thought they
could do it!
By this time, engineers had much more experience of major
tunnelling works. Many main line railways had long tunnels.
They had also worked underwater - Brunel completed a footway
tunnel under the Thames in 1843 - an 18 year struggle with
flooding. A submarine telegraph cable was laid across the
Straits of Dover in 1851. Elsewhere, a 5-mile tunnel through
the peaks of the Alps was started in 1857, and the Suez
Canal - the proudest feat of 19th century engineering -
opened in 1869.

Confident French and English engineers now approached the
task of planning to construct a 25-mile undersea tunnel in
earnest..... Back
to top

French engineer Thomé de Gamond and his railway
tunnel scheme of 1857 - then steamship ferries carried
350,000 passengers a year, 3/4 of them English. He estimated
the appeal of a 25 minute undersea crossing with no
seasickness would attract double the number - including many
more Continentals.

The problems
tunnellers faced:

geology - they had to check, and hoped to find
that a suitable rock for tunnelling stretched in an
unbroken bed across the channel;

ventilation - how to stop smoke from the steam
trains choking the passengers in such a long tunnel?

defence - the English were worried about
creating an easy route for invaders to cross the
Channel.

Frenchman Thomé de Gamond worked hard to
find convincing answers:
in 1857 his scheme was widely accepted in England and
France. After making many hazardous solo dives to check the
sea-bed, he proposed a rail tunnel, bored through the chalk
which he believed ran below the sea-bed.

His plan - see left - had an international port built
mid-way on an artificial island on the Varne sandbank. Steam
trains would run from the Paris-Amiens-Boulogne line on a
double track through a single gas-lit tunnel. Ventilation
was provided by the mid-way opening at the Varne.
Back
to top

First
serious attempts to build a
tunnelThe private railway companies either
side of the channel could now afford to put up the money for
a serious attempt - IF their governments would permit
it. Railway barons dreamed of a profitable long-distance
railway not just across the Straits of Dover, but across
Europe - which would generate huge volumes of new passenger
and freight traffic!

1870's: checking the
geologyEngland and France became quite friendly after
the Franco-Prussian war 1870-71. The cocky French had been
badly beaten; Paris had been beseiged, and a triumphant
German Kaiser was seen as a newly-powerful common enemy.

Both countries agreed to work together on a joint tunnel
scheme to bring them closer together. With government
approval, tunnel companies were set up to do the first
serious scientific exploration of the geology - to find out
just what rocks lay under the sea bed between Dover and
Calais....

The Lower Chalk bed proved the best part of the chalk for
tunnelling: it is....

soft but firm - easy to dig, but will stand up even
without supporting walls

waterproof - it is 80+% chalk, with some clay mixed
in

thick enough to hold a tunnel

1.
1876: French Channel Tunnel
Company uses the paddle steamer "Ajax" to take samples from
the seabed to check the geology was suitable for tunnel.2.
1870's - on land, shafts
were dug to check the chalk underground. There were no
problems at Sangatte on the French side, but at St.
Margarets (east of Dover), the shaft flooded through cracks
in the chalk. They switched work to west of Dover.Back to
top

1880-83:
trial tunnels dug either side1.
Engineers began boring
trial tunnels from both sides in 1881: this is the English
site, at the bottom of Shakespeare Cliff.2.
Both sides used improved tunnel boring machines, first
patented in 1875.3.
In 1882 the English Tunnel
Company faced political opposition: the two governments had
quarrelled over the Suez Canal and colonies in Africa. VIP
visits were arranged in an attempt to get British government
permission to complete the work - but the British army
objected. Here influential visitors head for the workface on
a workmen's train.4.
.At the undersea end of the tunnel: VIPs inspect the boring
machine in action - chalk slurry pours out from a conveyor
belt at the rear, while the cutting heads in front dig into
the chalk rock.

A technical success?The two tunnel companies started digging
seriously in 1881 from the cliffs between Dover and
Folkestone, and west of Calais (Sangatte).

Technically, it was a success - driven by compressed air,
the boring machines worked well, and there was so little
flooding they only switched the pumps on for half a day
every two weeks! Within the first year, each side had bored
almost 2 km of tunnel, and they expected to complete a 7
foot diameter pilot tunnel across the Channel within 5
years.

They planned the tunnel trains would also be powered by
compressed air - solving the problem of smoke and fumes.
Soon the invention of clean electric trains offered an even
better solution.

Tunnel abandoned - fear of a French
invasion
This aroused alarm amongst the British military, and in
1883, further building of the Tunnel was banned. The Tunnel
company suggested (in vain) that, as a safeguard, they could
instal an inlet to the sea half-way along the tunnel! A
soldier would be permanently on guard, ready to pull the
plug if the French should try a surprise invasion! They
offered to build a fort guarding the tunnel entrance, and to
wire it up with explosives ready to destroy the whole tunnel
or flood it with seawater.....

It was no good! The British generals did not trust the
French, and that was that. The French tunnellers gave up -
believing the British would always be stubborn about staying
as an "island fortress".

Meanwhile on the Dover side, though the Tunnel was
abandoned, they drilled their shaft deeper and in 1890
discovered coal and iron-ore seams - hidden extensions of
the coalfields of northern France and Belgium: see Formation
of coal)Back
to top

1914-18
- the tunnel could have supplied the TrenchesThe generals now wished the Tunnel had been
built!

During the First World War,
fresh troops, munitions and supplies had to cross the
Channel under constant fire from enemy ships, submarines,
airships and aircraft - needing the protection of the Dover
Patrol. Wounded soldiers were also in danger returning home
from the Front.

It was estimated that the Tunnel could have shortened the
war by 2 years - in fact, the Germans might not have invaded
France if the Tunnel had been built! As it was, the Germans
very nearly won.....

More talking - no
actionAfter the First World War, many politicians were in
favour of going ahead with a tunnel, and there were more
trial borings in the 1920's - but behind the scenes,
generals and diplomats who still mistrusted the French
quietly vetoed the scheme. Back
to top

Over the years, bridges as well as tunnels were proposed.
The big snag was the danger to shipping, especially in the
foggy turbulent Straits of Dover.

Newly completed tunnel in 1993 - it
followed more or less the same route underground as planned
in 1880 and 1974 - it could have been celebrating its
centenary!

1974-75:
the second attemptIn 1973, Britain finally joined France in the Common
Market AND both governments agreed to have another go at
building a tunnel. But in 1975, construction was again
abandoned because the British prime minister (Harold Wilson)
had to look for economies in a financial crisis caused by
dramatically rising world oil prices.

1987-94 - third time
lucky!Finally in the 1980s the British and French
governments commissioned more studies, and decided that a
"traditional" rail tunnel would be least risky and best
value for money - just as could have been built a century
ago, or 20 years ago, for a fraction of the price! They gave
the go-ahead to a private company using private money to
build a rail tunnel.

Work stated on both sides in 1987, and the fixed link was
opened in 1994 - nearly 2 years late, and way over
budget.

...but the tunnel doesn't
kill the ferriesIt was correctly predicted that cross-channel
traffic was growing so fast that there would be enough
business for both the tunnel and the ferries - who survived
by combining forces, concentrating on the Dover-Calais
route, and investing in giant super-ferries that could offer
cheaper fares. Back
to top

Checking
the geology AGAIN1980's engineers used new technology developed
for deep-sea oil exploration to check exactly what was under
the sea bed.

1.
Cross-section of the geology as known today - showing the
present tunnel, which follows the Lower Chalk most of the
way across, except for the under-land tunnel on the French
side.2.
They found hazardous
"buried valleys" on the sea bed, filled with mud and sand
rather than solid rock. The tunnel route had to keep to
solid rock.See 'How
the Channel was formed' for more about the
geology. Back to
top

How the
Tunnel operatesThere are two single-track rail tunnels, and a
third smaller service tunnel as an emergency exit (with
frequent cross passages). These were bored through the chalk
from either side, and met in the middle. They are lined with
concrete panels (on the French side, made from the Marquise
quarries).

The tunnel copies some of the Alpine mountain tunnels in
carrying cars and lorries on drive-on/drive-off shuttle
trains. Operated by Eurotunnel
"le Shuttle", these share the tracks with high speed
long-distance passenger trains run by Eurostar.
All trains are electric, and the twin tunnel While the
vehicle shuttle competes head-on with the ferries, Eurostar
trains regard their main competitor as the airlines. They
charge fares to match airline business tickets, and soon
siezed 80% of the London-Paris market. Back to
top

Cars just drive on the double-deck shuttle train: freight
lorries have their own trains.

Folkestone shuttle terminal next to the M20 motorway - 35
minutes from France.

High speed rail
linksIn 1993 a high-speed rail link opened from the
French-side Tunnel portal to Lille, and from there to Paris
and (more recently) Brussels. Eurostar trains had to "crawl"
through Kent at 70 miles an hour on normal suburban lines,
speeding up once they reached the Tunnel and racing through
the French countryside.

On the English side, the first stage of a purpose-built
line from the Tunnel to London is planned to be open in
2003(see
links below)

Future schemes: a drive-through tunnel
for cars? ...or a second rail tunnel for Eurostar passenger
trains and the vehicle-carrying shuttle

A second
tunnel?As part of the conditions under which the Tunnel
Company were granted a monopoly for 25 years, they had to
produce a feasability study for a second tunnel.

Although cross-channel traffic is increasing steadily,
and the first tunnel covers its running costs, it has made
slow progress in paying off its enormous debt from the
construction. No-one is likely to be keen to build a second
tunnel in the near future - so this feasabilty study will
probably go no further.

A road or rail tunnel?Technology has improved so much that it would now
be possible to consider a larger bore drive-through tunnel
for cars (lorries emit too much fumes) as an alternative to
one carrying extra train tracks. Back to
top